The Spire Shells and Flood Shells 



operculum horny. Foot very broad; snout extensible; gill 

 present, but the mollusk breathes air. 



P. lapidaria, Say, is a little pebble-like snail, scarce large 

 enough to earn a name. It is found in moist situations, under 

 stones, on river banks, and is able to crawl along the surface of 

 the water with its shell hanging downward. But it is uncomfort- 

 able in water. On land it progresses by fastening the tip of the 

 snout, and drawing the body up to it, thus taking "steps." 

 Length, i inch. 



Habitat. — Michigan and Missouri to Georgia and New York. 



P. Californica, Pils., has a turreted-conic, thin, brown shell 

 with a pit underneath the rounded whorls. Length, i inch. 



Habitat. — Small streams about San Francisco Bay. 



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